1. Field of the Invention
This invention relates to a multiple cylinder hot gas engine heater head in which a plurality of tubes connect the cylinders with the corresponding regenerator housings and in which each tube has a first curved part of a shape which corresponds substantially to the shape of an involute curve on a cone, and in which tubes are juxtaposed so that constant, small gaps between the curved parts are obtained.
2. Description of the Prior Art
The prior art is elucidated best e.g. in U.S. Pat. No. 4,345,645. In this prior art the first curved parts of the tubes connect a quarter circle segment manifold of a cylinder with two circle segment regenerator manifolds arranged at a larger distance from a central axis via second curved tube parts following involute curves on the same cone but at such larger base circle that a multiple of tubes may be arranged.
The said known type of heater head is adapted to be heated by solar radiation, but although the greater parts of the tubes may be exposed to the sun, it still comprises tube parts which are shadowed and thus increases the dead volumes of the engine.